Device for the manufacture of a branch to a straight tube

ABSTRACT

The invention relates to a device for the manufacture of at least one branch to a tub comprising a splitted die provided with a channel for the tube, an external clamp for the tube at one side of the die, a cavity for the branch and an additional cavity at the other side of the die in which a movable die part is provided, and a mandrel equipped with an internal clamp for the tube on the spot of the movable die part, which mandrel together with the movable die part is movable in the direction of the external clamp in order to upset the tube between the clamps so that the material of said tube bulges in the cavity to form a branch.

[ Jan. 23, 1973 [54] DEVICE FOR THE MANUFACTURE OF A BRANCH TO A STRAIGHT TUBE [75] Inventors: Arie Verkaik, Maas sluisi Cornelis Leendert Funcke, Apeldoorn, both of Netherlands [22] Filed: Dec. 2, 1970 [21] Appl. No.: 94,430

[30] Foreign Application Priority Data Dec. 17, 1969 Netherlands ..69l8975 [52] US. Cl. ..72/60, 29/157 T [51] Int. Cl. ..B2ld 26/04 [58] Field of Search ..29/157 T; 72/57, 58, 60, 61,

[56] References Cited UNITED STATES PATENTS Johnson ..72/6O Taylor ..29/1 57 T FOREIGN PATENTS OR APPLICATIONS 583,147 9/1959 Canada ..72/62 692,555 8/1964 Canada ..72/59 723,937 1/1932 France ..72/62 Primary ExaminerRichard J. Herbst AttorneySpencer & Kaye ABSTRACT The invention relates to a device for the manufacture of at least one branch to a tub comprising a splitted die provided with a channel for the tube, an external clamp for the tube at one side of the die, a cavity for the branch and an additional cavity at the other side of the die in which a movable die part is provided, and a mandrel equipped with an internal clamp for the tube on the spot of the movable die part, which mandrel together with the movable die part is movable in the direction of the external clamp in order to upset the tube between the clamps so that the material of said tube bulges in the cavity to form a branch.

1 Claim, 4 Drawing Figures PATENTEDJAH 23 ma 3, 7 1 2 O9 7 SHEET 1 BF 2 FIG. /2 7 e 5 24 e ATTORN.

PATENTEUJAN 23 L973 4 I 3.712.09 7 sum 2 0F 2 FIE-3.4

INVENTORS. Arie Verkaik BY Cornell's Leenderr Funcke ATTORNEYS.

TO A STRAIGHT TUBE The invention relates to a device for the manufacture of a branch to a tube and to a tube or a piece of tubing provided with one or more branches.

It is known in the art to manufacture an incipient part of a branch to a short piece of tubing with the aid of a mandrel that is placed into the piece of tubing and two die sections that each enclose a tube end completely. The two die sections are moved axially towards each other and the piece of tubing is compressed over the whole length. A central part of the piece of tubing bulges through a lateral opening that remains open between the die sections when these rest abutting on each other. During this bulging the material of the central part of the piece of tubing is only partially supported so that an irregularly shaped closed bulge arises that has to be opened with other tools and widened out into the desired shape of the branch.

It is also known in the art to re-shape a short piece of tubing into a branch around a hollow mandrel in a closed splitted die with a lateral cavity, with the aid of pressure plugs, which in the die compress the ends of the piece of tubing axially, and an incompressible medij um, which is enclosed in the piece of tubing with the pressure plugs and is brought under pressure, causing the material of the piece of tubing to be expanded into a branch in the cavity. In doing so, a drawback is that these branches can only be manufactured from short pieces of tubing because with long pieces of tubing the die sections or the pressure plugs, which act at the ends of the piece of tubing, become very long, like their guiding means, and in these dies the full length of the piece of tubing must be compressed in axial direction until plasticity occurs. This requires much friction of the tubing against the die walls and consequently energy, whereas only a small part of the energy is used to reshape a central part of the piece of tubing into the branch.

Moreover, it is known in the art to provide a bulge in a random place in a tube by heating the tube locally so strongly'that it becomes plastically re-shapable and to upset it in a splitted die with a lateral opening by bringing the cold sections that projects beyond the die clamps gripping around the tube. Here also the desired shape must be given to the'branch with other tools.

The object of the invention is a device with which in a random spot in a tube without heating a full branch is simultaneously manufactured without parts of the tube that lie outside the device being brought under stress. For that purpose a device for manufacturing a branch to a tube, provided with a mandrel and a closed splitted die with a cavity for the branch according to the invention, is equipped with at one side of the die an external clamp for the tube and at the other side an additional cavity, in which a movable die part is provided, whereas the mandrel is equipped with an internal clamp for the tube on the spot of the movable die part together with the latter is movable in the direction of the external clamp.

The tube is upset by the movement, with regard to the remaining closed die sections with the external clamp, of the mandrel with the internal clamp together with the movable die part, a part of the tubing entering the cavity for the branch and completely following the towards each other in the axial direction withthe aid of shape of that cavity, because also a liquid pressure is provided in the tube that only acts on the tubing present withinthe die, because according to the invention on the mandrel beyond the internal clamp and beyond the external clamp sealings are provided between the tube wall and the mandrel.

According to the invention the sealing beyond the external clamp may be provided in an immovable position on to the mandrel whereas the other sealing on the mandrel may be movable and attribute to clamping of the internal clamp, because it tightens against the tube wall clamping segments on a conical part of the mandrel, which are provided with teeth.

In order to take care that in the material of the branch a compressive stress comes to prevail in the cavity for the branch, according to the invention another pressure plug is provided movable so as to flatten the cover slab of the branch and to exert a compressing effect on the material of the branch.

When in the branch a connecting piece of tubing must be capable of being connected it is advisable to construct in the device the cavity for the branch in such a way that a branch with a flared part is produced. For that purpose according to the invention an enlargement for the flared part is provided in the cavity over a bearing edge in the splitted die, while in the movable die part, whose width is equal to the nominal outside tube diameter, the sharp front edges of the enlargement for the flared part come to an end over 'a bearing edge on the spot of the edge of the enlargement in the splitted die.

In order to remove the cover slab from the branch, according to the invention a tool is provided for the branch with an annular cutter in an annular adjustingsleeve, the flared part of the branch bearing on the bearing-edges in the die and acting as counterpart of the cutter.

The invention is further elucidated below with the aid of a schematical drawing of a preferred embodiment ofa device according to the invention.

FIG. 1 shows a lengthwise cross-section of that device close byv the mating-surface of a closed splitted die with a movable part in the initial position.

FIG. -2 shows an upper view of the device in the same position. i

' FIG. 3 shows a lengthwise cross-section as FIG. I but with the die parts in the final position.

FIG. 4 finally shows the device with an additional pressure plug provided with an annular cutter.

Tube 1 is placed in a splitted die and on closing the latter is held so tightly by clamping pieces 3 provided with sawteeth that on later re-shaping of the tube the clamped part remains in its place.

In die halves 2 immediately behind clamping parts 3 a cavity 4 is recessed in he shape of half a branch and an additional cavity 5 blends with it, with a width equal to the nominal outside diameter of the tube, in which a movable die part 6 with the other half of the shape of the branch is slidable according to the center line of tube 1. ln cavity 4 and partially in additional cavity 5 a pressure plug 7 is provided, which under the influence of a pressure force 8 is movable in the direction of the center line of the branch to be shaped.

Into tube 1 a mandrel 10 is slid in which a bore 11 is provided through which a liquid can be supplied under pressure to that part of the tube that has to be shaped into a branch.

On to mandrel 10 a fixed sleeve 12 is provided for sealing the liquid against the tube wall and at the end of the mandrel another sleeve 13 is attached. This latter sleeve 13 with its bearing-ring 14 is slidably connected on to mandrel 10 against the pressure of a spring 15. Mandrel 10 is slide into the tube in such a way that fixed sleeve 12 comes near clamping parts 3 and sleeve 13 falls within the die with movable part 6 in the initial position. Split die 2 is so long that sleeve 12 on mandrel 10, when it is in its final position, also still falls within the die.

When mandrel 10 is brought into its place liquid can be admitted through bore 11 and brought under pressure. Sleeve 12 immediately seals against the tube, but due to the pressure of the liquid, sleeve 13 with bearing-ring 14 is shifted over mandrel 10 into tube 1 against the pressure of spring 15 until bearing-ring 14 becomes jammed against end stop 16 of the mandrel. Then sleeve 13 seals completely against the tube wall. When bearing-ring 14 is shifted over mandrel 10 this bearing--ring pulls along a number of rods 17, which are connected to clamping segments 18 provided with sawteeth and bearing on conical parts 19 of the mandrel. Clamping segments 18 are transferred over conical parts 19 of the mandrel and pressed outwards against the action of two annular springs 20 embracing the segments. The sawteeth grip with great force in the tube wall and in this spot mandrel 10 will form a unit with tube 1.

Then a pulling force 9 is exerted on the end of mandrel l projecting beyond tube 1 and the end of mandrel 10 is gradually moved in the die into the direction of fixed clamping parts 3. By this movement of the mandrel clamping segments 18 are still extra pressed against the tube walls and the right-hand part of the tube will move along with mandrel 10. Movable die part 6 is at the same time moved along with mandrel 10 by pull rods that are not drafted and at the same time the pressure of the liquid in the tube between sleeves l2 and 13 is raised. Under these circumstances the material of tube 1 between the internal clamp formed by segments 18 on mandrel l0 and the external clamp formed by clamping parts 3 can only move laterally into cavities 4 and of the die and as well by the pressure of the liquid begin to bulge, pressing itself towards cavity 4 against the die walls in the curvatures of the die parts and remaining in those places. On shortening the distance between the clamps by the movement of the mandrel the tube gradually deforms into a complete branch in the remaining space ofcavity 4.

The tube part that will form the cover slab of the branch is curved convex under the influence of the liquid pressure and the material is under great tensile stresses until it contacts pressure plug 7 and begins to flatten again. When mandrel and movable die part 6 have come in the final position and the die for the branch is completely closed an additional pressure force 8 is exerted on pressure plug 7 as a result of which a complete flattening of the convex cover plane is attained. By the co-operation of the liquid pressure in the tube and the additional pressure force 8 on pressure plug 7 the tubing material is completely pressed against the walls of the die cavities in every nook and corner and the original tensile stress in the material of the branch is converted into a compressive stress. This internal compressive stress in all parts of the branch and its connection to the tube does not only give a great strength against the later liquid pressure or gaseous pressure in a duct but especially a greater resistance against stress corrosion.

in a device according to the invention an ordinary branch can be manufactured but in the device according to the example drafted a branch with a flared end is manufactured. The outer diameter of this end is the double wall-thickness greater than the outer diameter of the tube, in order that in such a flared part a tube with the same nominal measure can be inserted and soldered, if desired.

So as to obtain room for the flared part in the die in die parts 2 and 6 edges 21 and 22 are provided over which cavity 4 has a greater diameter. Movable part 6 of the die and cavity 5 have only a width that is equal to the nominal outer diameter of the tube, but cavity 4 in die 2 for the flared part is provided with an enlargement 23 over edge 21. Die part 6 is also enlarged over edge 22 and consequently sharp front edges 24 of the enlargement for the flared part are no longer off the center line of the branch but lie retracted in relation to front edge 25 of the lower part of die part 6 with the nominal tube diameter.

When the tube with its flared end has got its shape in the die it is closed by the flattened cover slab and this has to be removed yet. With the method known in the art for shaping a branch the cover slab is cut with a saw and the branch opened and next a flared end is manufactured with the aid of an expanding tool. In contrast with that known method in the device according to the invention firstly the branch is brought completely into the flared shape and only thereafter the opening is cut.

For that purpose after the pressure of the liquid is let off and pressure plug 7 has been removed an additional tool is inserted into the die. In FIG. 4 it is shown that in cavity 4 an annular adjusting-sleeve 30 is placed with a wall-thickness corresponding to the wall-thickness of the branch. Within this adjusting-sleeve 30 an annular cutter 31 is provided with a sharp roof-shaped cuttingedge 32 at the outer periphery. Within cutter 31 again there is a pressure plug 33. Adjusting-sleeve 30 and pressure plug 33 are interconnected by a bolt 34, which goes through slotted holes 35 of cutter 31. The assembly of adjusting-sleeve and pressure plug is pressed on to the top of the branch by an external force 36 and then cutter 31 is made to cut by a second force 37. This is a schematic representation of the issue, which can be solved constructionally in a way known in the art with hydraulic, pneumatic or mechanic means.

As counterpart at the cutting process acts the wall material of the flared part that again is supported by edges 21 and 22 in die parts 2 and 6. Cutting-edge 32 cuts the cover slab of the branch exactly and presses it into the flared part, but now as a loose cover 38 such as is drawn in the right-hand side of FIGA. When the tube with the branch shaped is taken from the device the cover can be removed. ln many cases it is desirable, however, that the loose cover remains until mounting of a tube in the branch is going to be effected. For the cover provides protection against dirt or damage of the interior of branch or tube.

With the device according to the invention is possi' ble to provide a number of branches one after another in tube 1 by advancing along the tube in relation to the die and the mandrel and to manufacture another branch. The only condition is that on moving the mandrcl with the clamped tube section for shaping a next branch the branch already formed does not abut against the device.

it is possible to manufacture loose tees from a tube with a number of branches after one another by cutting the tube at the desired distances and in that way an automatic production of tees can be realized.

The other possibility is that at specific places branches are providedgn a great number of tubes which then for instance are mounted in house building as ancillary ducts and laid into concrete in walls or floors, if desired.

Afterwards the covers are removed from the flared parts and further connections are constructed. Through this standardization takes place and a great saving of labor is obtained in assembling.

In the device drafted the center line of the branch is slant in relation to the center line of the tube. It is clear that a branch perpendicular to the tube can be manufactured in the same way.

Further is it possible to manufacture branches with or without a flare but with a nominal outside diameter different from that of the original tube. In this case the width of movable die part 6 must be adapted to the width of the nominal tube diameter of the branch.

The front edges of the die planes on this die part 6 must be sharp, however, so that no upsetting of seams on the branch can occur.

We claim:

1. A device for the manufacture of a branch to a tube comprising in combination:

a. a split die with mating halves to receive the tube therebetween, said die having a forward section with means for externally clamping the tubular member and with a rearwardly opening cavity, said die also having a rear section in which a movable die part, with a forwardly opening cavity, is mounted for slidable movement over the tubular member toward said forward section of said die;

. a mandrel which is received in the tubular member positioned within said die, said mandrel including a recess through which a liquid can be admitted under pressure to a central area of the mandrel within the tubular member, said area being defined at one end by agfirst sleeve which lies forward of said means for vextcrnally clamping the tubular member in said die and which is urged into sealing engagement with the tubular member by the liquid, and at the other end by a spring biased second sleeve which is disposed within said rear section of said die and which is movable by the liquid against the spring bias to a point of sealing engagement within the tubular member;

c. a conical portion within said central area and on which a plurality of segments are slidably mounted, said segments being connected to said second sleeve and movable into clamping engagement with the tubular member when said second sleeve is moved to sealing engagement with the member whereby, as said movable die part and said mandrel are simultaneously moved orward,

the tubular member is deformed outwardly into the space between said forwardly and rearwardly opening cavities.

UM En STATES ?A'EiEN'l other @ERHHQAEE GE QQRREQ'NQN Patent No. 3,712 Dated January 1973 fg) Arie Verkaik and Cornelis Leendert Funcke It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the headingof thepatent, line 7, change v "Natuu'rivetenschappelyk" to -Natuurwetenschappelijk. Column 1, line 61, before "together" insert and Column 2, line 57, change "he" to --the Column 3, line 8, change "slide" to '-slid--.

Signedzarid sealed this 10th clay of July 1975.

(SEAL) Attest:

Rene Tegtmeyer EDWARD M. FLETCHER ,JR.

Actlng Commissioner of Patents Attesting Officer ORM PC4050 (10-69) -pc Q37 .p59 u.s. GOVERNMENT PRINTING OFFICE: 1959 0-356-334 

1. A device for the manufacture of a branch to a tube comprising in combination: a. a split die with mating halves to receive the tube therebetween, said die having a forward section with means for externally clamping the tubular member and with a rearwardly opening cavity, said die also having a rear section in which a movable die part, with a forwardly opening cavity, is mounted for slidable movement over the tubular member toward said forward section of said die; b. a mandrel which is received in the tubular member positioned within said die, said mandrel including a recess through which a liquid can be admitted under pressure to a central area of the mandrel within the tubular member, said area being defined at one end by a first sleeve which lies forward of said means for externally clamping the tubular member in said die and which is urged into sealing engagement with the tubular member by the liquid, and at the other end by a spring biased second sleeve which is disposed within said rear section of said die and which is movable by the liquid against the spring bias to a point of sealing engagement within the tubular member; c. a conical portion within said central area and on which a plurality of segments are slidably mounted, said segments being connected to said second sleeve and movable into clamping engagement with the tubular member when said second sleeve is moved to sealing engagement with the member whereby, as said movable die part and said mandrel are simultaneously moved forward, the tubular member is deformed outwardly into the space between said forwardly and rearwardly opening cavities. 